Statistic Property of Long Duration Microwave Type Ⅲ Bursts at 2.6~3.8 GHz

Through a systematical survey of the data in 2.6~3.8 GHz from the Radio Spectrometer in Beijing,73 isolated microwave type Ⅲ solar radio bursts with characteristic life time of 20 s are selected.The frequency distribution of their full width at half maximum(FWHM) is acquired.The examination of the empirical law in the metric and decimetric wavelengths is made using the observed data and result shows that the life time of the type Ⅲ bursts at 2.6~3.8 GHz is inverse propertional to their frequency,but the corresponding factors are very different compared with those of meter wave and decimeter wave.